One of the key criticisms against cellulosic ethanol production from crops like switchgrass is that it will consume more fossil fuel than energy produced. However, this is not factually accurate. There are currently three methods to convert cellulosic biomass to ethanol: acid hydrolosis; thermal gasification, and enzymatic reduction hydrolosis.

 

Criticisms of late have focused on the least effective of the three, acid hydrolosis. A study by the National Renewable Energy Laboratory showed acid hydrolosis to be an effective technology with softwood biomass conversion.

 

Thermal gasification converts a solid biomass to a gas that can be used in conversion equipment like gas turbines and gas engines for production of heat and electricity. The gas can also be converted to ethanol through a biological microorganism process, or through a catalytic reactor. Both of these thermal gasification methods are proving cost-effective with cellulosic biomass.

 

The most effective method is enzymatic reduction hydrolosis. Companies like Iogen (